Final answer:
The equipment used to separate or connect 12KV bus actions includes circuit breakers, disconnectors, and switchgear, which are essential for the safety and reliability of power transmission systems.
Step-by-step explanation:
The equipment used to separate or connect 12KV bus actions in a power transmission system typically includes circuit breakers, disconnectors (also known as isolators), and switchgear. The circuit breaker serves as a protective device that can interrupt fault currents and is capable of switching the power line off for maintenance or operational purposes. The disconnector or isolator primarily functions to isolate a part of the circuit for safety when maintenance is being done. It ensures there is a visible gap in the circuit. Switchgear, on the other hand, is a combination of electrical disconnect switches, fuses, or circuit breakers used to control, protect, and isolate electrical equipment.
In the context of power transmission, particularly considering that voltages ranging from 120 to 700 kV are used to transmit power over long distances, the equipment must withstand high voltages and ensure the safety and reliability of the power system. Power is typically stepped up with a transformer at the power station exit for efficient transmission over distances, and then stepped down from high voltages, such as 12 kV to 240 V, for safe usage in homes, which is done through substations as per Figure 15.20. Therefore, the outlined equipment for bus actions is critical in managing and operating the power transmission system effectively.